97 buick lesabre limited

inherited 97 buick lesabre, mother sideswiped a small truck had to replace driver’s side frt quarter panel & door, and hit the side of the garage and replaced the passenger side frt panel and door. After driving the car and getting above 45 mph the car kinda hesitates or drags like not enough gas or fluctuating power. Is it the computer system since the security dash light stays on on the security system is funky, is it carbon build up, or what

The security light and accidents probably have NOTHING to do with yout current problem. Take a look at the inline fuel filter. There is also a filter on the fuel pump in the tank. That can’t be replaced without dropping the tank and pulling the pump. If there is a “check engine light” AKA MIL, take it to your local Autozone (if you have one) and have them run a free scanner check on it. It may also have low fuel pressure caused by a bad fuel pump. It’s easy to check with the right equipment, but I don’t think Autozone will do it for free. You can always ask.

Yes, you should replace the fuel filter. It’s likely it’s original and dirty. A dirty fuel filter will limit acceleration So will high mileage spark plugs and spark plug wires.

The security light issue is likely a loose or shorting out wire to a door.

what about the EGR valve? it only does this after driving over 20-30 minutes and in warm-hot weather. Someone else mentioned MAP??

oh, the car only has 78000 miles on it, has new alternator, new belts, new plugs and wires, and just had a tune up